Why Choose the HKS Super Hybrid Turbo Kit for Your Q50 VR30DDTT?

The Infiniti Q50 VR30DDTT is a potent platform from the factory, but the twin-turbocharged V6 has significant untapped potential. The HKS Super Hybrid Turbo Kit is one of the most respected upgrades in the Japanese performance community, offering a perfect balance of quick spool, higher flow, and reliability. Unlike some larger turbo options that sacrifice low-end response for peak horsepower, the Super Hybrid design uses advanced compressor and turbine wheel technology to deliver meaningful power gains across the entire rev range. This guide walks you through the complete installation process, from prep work to final test drive, ensuring you get the most out of your upgrade.

Before lifting the hood, understand that this installation requires mechanical experience with turbo systems, proper tooling, and patience. If you are not comfortable working with engine oil, coolant, and precision fasteners, consider having a professional shop oversee the job. For those ready to take it on, let's get started.

Tools, Materials, and Safety Gear

Essential Tools

  • Complete socket set (metric, 1/4" and 3/8" drive) – extensions, swivels, and universal joints will save you headaches on tight fasteners.
  • Torque wrench (ft-lb and in-lb ranges) – critical for turbo bolts, oil lines, and banjo fittings.
  • Combination wrenches (10mm to 19mm, plus flare nut wrenches for fuel and oil lines).
  • Screwdrivers (flathead, Phillips, and JIS) – the VR30DDTT uses JIS cross-head fasteners in several spots.
  • Pry bar or trim removal tools – for disconnecting hoses and plastic clips.
  • Pick and hook set – to remove stubborn O-rings and vacuum lines.
  • Jack and jack stands or a lift – you will need access underneath the vehicle.
  • Oil catch can or drain pan – at least 8-quart capacity.
  • Shop towels, brake cleaner, and a wire brush – cleanliness is non-negotiable when working with turbochargers.

HKS Kit Contents and Consumables

Your HKS Super Hybrid Turbo Kit (typically part number 14007-TA005 or similar for VR30DDTT) should include:

  • Two HKS Super Hybrid turbos (high-flow billet compressor wheels, upgraded bearings)
  • HKS wastegate actuators (if not integrated)
  • HKS boost hoses and silicone couplers
  • New gaskets and sealing rings
  • Installation hardware (studs, nuts, washers)

You will also need:

  • New OEM or aftermarket gaskets (turbo-to-manifold, downpipe-to-turbo, oil drain gasket) – do not reuse.
  • High-temperature silicone hose for coolant and oil lines if the originals show age.
  • Engine oil and filter – 5W-30 or 0W-40 depending on your climate; plan for a full oil change after the install.
  • Antifreeze – if you open the coolant system, bleed and refill properly.
  • Thread locker (medium strength) and anti-seize compound.

Safety First

Turbochargers operate at extreme temperatures and pressures. Always wear heat-resistant gloves and safety goggles. Work in a well-ventilated area – gasoline fumes and coolant vapors are flammable and toxic. Keep a fire extinguisher nearby. Ensure the engine is completely cool before starting (ouch, burns are common). Disconnect the battery negative terminal to prevent accidental shorts and electronic module damage.

Preparation: Setting Up for Success

Workspace and Vehicle Positioning

Raise the Q50 on jack stands or a lift so you have ample room to work below the engine bay. Remove the under-engine splash shield. Allow the vehicle to sit for at least an hour after a short drive to cool down the exhaust and turbo components – metal expands when hot and tightening bolts on hot hardware can lead to warped flanges.

Disconnect the Battery

Start by disconnecting the negative terminal. Secure the cable so it cannot accidentally contact the terminal. This step is often skipped but is critical for the VR30DDTT’s sensitive electronic throttle control and ECU.

Remove the Engine Beauty Cover

Using a socket set (10mm), remove the four bolts holding the plastic engine cover. Lift it straight up – there are no hidden clips. Set it aside on a clean surface.

Drain the Engine Oil

Place an oil catch can under the oil pan (drain plug is 14mm). Remove the drain plug and let the oil drain. While it drains, remove the oil filter to allow complete evacuation. This step prevents messy spills when you disconnect turbo oil feed and drain lines. After the oil is fully drained, reinstall the drain plug with a new crush washer and torque to 22 ft-lb (or per your vehicle’s manual).

Remove Necessary Components for Access

The VR30DDTT engine bay is tight. To reach the stock turbos, you will need to remove several items:

  • Air intake assembly (both sides) – disconnect MAF sensors, unbolt intake tubes.
  • Charge pipes (intercooler to throttle body and from turbos to intercooler).
  • Coolant expansion tank (mounted on the driver side) – carefully unplug the low-level sensor and remove bolts.
  • Heatshields over the stock turbos (these are often rusted; use penetrating oil).
  • Accessory belt (if required for your model year) – use a 15mm wrench on the tensioner.
  • Front bumper and intercooler are not strictly necessary but can simplify lower turbo access.

Removing the Factory Turbos

Unbolt the Turbochargers

Working from above and below, you will see the two small Mitsubishi or IHI turbos bolted to the exhaust manifold. Each is secured by four M8 studs and nuts (or bolts, depending on year). Use a penetrating spray on the studs and let it soak for five minutes. Do not force them – broken studs require removal of the manifold. Use a combination of sockets and swivels to reach the rear turbo (closest to the firewall), which is the more challenging one.

Disconnect Oil and Coolant Lines

Locate the oil feed line (usually a braided steel line with a banjo fitting at the turbo). Use a flare wrench to avoid rounding the nut. The oil drain line is a large rubber hose clamped to the oil pan – loosen the clamp and carefully slide it off. Coolant lines are typically push-to-connect or use small bolt flanges. Drain any remaining fluid into a container. Label each line with masking tape to avoid confusion during reassembly.

Remove Downpipes and Exhaust Components

The downpipes are bolted to the exhaust manifold. Unbolt the downpipe-to-turbo flange (three nuts each) and disconnect the O2 sensors (18mm socket). Support the downpipe as you lower it to avoid bending the flex joint. If your Q50 is AWD, the front driveshaft may need to be partially lowered to remove the driver-side downpipe.

Extract the Old Turbos

With all lines disconnected and bolts removed, carefully wiggle each turbo out of the engine bay – the rear one often exits from the bottom. Inspect the mounting flanges for any carbon buildup or debris. Clean them with a wire brush and brake cleaner. This is also a good time to replace the exhaust manifold gaskets (recommended) and any heat shields that are damaged.

Installing the HKS Super Hybrid Turbo Kit

Prepare the HKS Turbos

Before installation, compare the HKS units to the stock ones. The Super Hybrid turbos are slightly larger but use the same mounting pattern. Check that the wastegate actuator brackets clear the engine block. Apply a thin coat of anti-seize to the wastegate actuator rod threads (if adjustable). Rotate the compressor wheel by hand to confirm smooth rotation – it should spin freely with light resistance due to the upgraded bearings.

Install New Gaskets

Place new OEM or HKS-provided gaskets on the exhaust manifold studs and the downpipe flanges. Ensure the gaskets are seated perfectly flat – any misalignment will cause exhaust leaks and reduced performance. Some builders prefer a thin layer of copper gasket sealant as an added measure, but it is not required.

Mount the HKS Turbos

Lift the turbo into position (rear first, then front). Slide the mounting studs through the gasket and turbo flange. Hand-tighten the nuts, then torque to the manufacturer’s specification – typically 20-25 ft-lb for M8 studs. Use a cross-pattern to ensure even clamping. Reconnect the downpipe to the turbo flange, using new gaskets and torque to 30-35 ft-lb. Do not fully tighten the downpipe until all mounts are aligned.

Reconnect Oil and Coolant Lines

Attach the oil feed line to the turbo using new copper washers on each banjo fitting. Torque the banjo bolt to 25-30 ft-lb. For the oil drain line, apply a light coat of engine oil to the O-ring and push the hose over the turbo drain barb, then tighten the clamp securely. Reconnect coolant lines in the same manner, checking that the quick-connect fittings click into place. No leaks allowed – double-check each connection.

Reinstall Accessories and Charge Pipes

With both turbos bolted, reattach the charge pipes using the HKS-supplied silicone hoses and T-bolt clamps. Ensure the clamps are oriented for easy re-tightening. Reinstall the coolant expansion tank, air intake assembly, and any heatshields removed earlier. Reattach the accessory belt and tensioner. Replace the engine beauty cover but do not tighten fully until you confirm boost hoses do not rub against it.

Refill Fluids

Add new engine oil – the VR30DDTT takes about 5.5 quarts with a filter change. Use a high-quality synthetic oil (5W-30 or 0W-40). If you opened the coolant system, refill with Nissan/Longlife blue coolant mixed 50/50 with distilled water and bleed the system per the service manual (run engine with heater on full, burp the coolant line).

Post-Installation Checks and Tuning

Battery and Electrical

Reconnect the negative battery terminal. Recheck all electrical connectors – O2 sensors, MAF, wastegate solenoid, and boost controller if applicable. Turn the ignition to the ON position without starting and let the fuel pump prime. Check for any illuminated warning lights on the dash – if the check engine light stays on, scan for codes before starting.

Initial Startup and Leak Test

Start the engine and let it idle for 2-3 minutes. Listen for any unusual noises – rattling, screeching, or whining from the turbos. A smooth, low whistle is normal as the bearings and seals break in. Check all oil and coolant connections for drips. Rev the engine gently to 2000-2500 RPM and hold for a moment – this helps seat the new rings and fill the turbo center section. After shutdown, inspect the ground for fluid puddles.

Bleeding the Coolant System (If Opened)

If you drained coolant, use the bleeding procedure: remove the radiator cap (cold engine), start the engine, turn the heater to max temp and low fan, and watch for bubbles to stop. Top off the reservoir. Repeat after a short test drive.

Test Drive and Boost Monitoring

Take the Q50 for a gentle 10-15 minute drive, avoiding hard throttle. This allows the turbos to heat-cycle and the ECU to adapt to the reduced backpressure. Gradually increase boost load – accelerate at medium throttle in third or fourth gear. The HKS turbos should spool noticeably earlier than stock, with boost building around 2500-2800 RPM vs. the stock 3000+ RPM. Do not exceed 10-12 psi on the factory tune – the HKS turbos can push much higher, but the stock fuel system and ECU logic are not calibrated for the increased air volume.

Important: The HKS Super Hybrid Turbo kit is a major performance upgrade that demands a proper tune. You have two options:

  • Custom ECU flash (Ecutek, Cobb, or UpRev) – enables full optimization of fuel, timing, and boost. Expect 500-550 whp on 93 octane pump gas with the appropriate supporting mods (fuel pump, injectors, intercooler).
  • Piggyback or boost controller – only recommended if you keep boost conservative and monitor AFR closely. A professional dyno tune is the safest path.

Find a tuning shop familiar with VR30DDTT platforms or reputable remote tuners. Do not run high boost without upgrading the HPFP or low-pressure fuel pump.

Conclusion and Next Steps

The HKS Super Hybrid Turbo Kit transforms the Q50 VR30DDTT from a quick luxury sedan into a genuine performance weapon. By installing the turbos yourself, you save significant labor costs and gain intimate knowledge of your engine bay. The key to longevity is meticulous attention to torque specs, cleanliness, and a proper tune. After 500-1000 miles, re-torque all turbo fasteners and check for unusual wear. Consider upgrading your intercooler, intake, and exhaust to match the increased flow potential.

For further reading and community support, check out dedicated forums like Q50 Forum and the official HKS Super Hybrid product page. Parts and kits can be sourced from trusted retailers such as Z1 Motorsports or Enjomo Racing (links for reference). With careful installation and responsible tuning, your Q50 will reward you with a thrilling driving experience for years to come.